数据量过大需要分批次操作List

Common Util:

private <T> List<List <T>> splitList(List<T> sourceList, int groupSize) {
        int length = sourceList.size();
        int num = (length + groupSize - 1) / groupSize;

        List<List<T>> targetList = new ArrayList<>(num);
        for (int i = 0; i < num; i++) {
            // start index
            int fromIndex = i * groupSize;
            // end index
            int toIndex = (i + 1) * groupSize < length ? (i + 1) * groupSize : length;
            targetList.add(sourceList.subList(fromIndex, toIndex));
        }
        return targetList;
    }

Test:

@Test
    public void testSplitList(){
        List list = new ArrayList();
        list.add("1111");
        list.add("2222");
        list.add("3333");
        list.add("4444");
        list.add("5555");
        list.add("6666");
        list.add("7777");
        list.add("8888");
        list.add("9999");
        List<List> lists = splitList(list, 5);
        for (List list1 : lists) {
            System.out.println(list1);
        }
    }